Kim Jong-un’s wife has made a rare public appearance alongside the North Korean leader at a celebration of the pariah state’s advancing nuclear capabilities.

Ri Sol-ju was photographed at a gala banquet for the engineers who conducted country’s most powerful nuclear test to date last Sunday.

The dictator’s wife has barely been seen in public in recent years, prompting speculation she may have given birth to the couple’s third child recently.

In 2016 she didn’t make a public appearance for more than seven months, initially raising fears she may have fallen from favour. She emerged again in December to accompany her husband at an air combat training competition.

Kim, 33, broke with tradition when he was first appeared in public with Ri in 2012 and since then North Korean media has referred to her has his wife. Neither Mr Kim’s grandfather, Kim Il-sung, nor father, Kim Jong-il, were ever photographed with their wives or partners in public.

Ri and Kim are reported to have met around 2010 when she was a member of the country’s Unhasu orchestra. The 27-year-old First Lady of the impoverished state is said to have a penchant for luxury goods and was spotted in 2012 with a Dior handbag worth over £1,000.

The pair have two children, whose genders are unknown. It is unusual for North Koreans to have more than two children, but Kim may have felt pressure to have a third if the first two were girls.

Kim and Ri visiting the Mangyongdae Revolutionary School in Pyongyang earlier this year Credit: AFP

Ri’s latest appearance comes amid a dramatic ratcheting up of tensions in south east Asia over North Korea’s nuclear arms tests.

British Defence Secretary, Sir Michael Fallon, said over the weekend that the UK is now under threat from the rouge nation’s advancing nuclear capabilities.

North Korea’s nuclear tests Blasts gain in strength

The celebration is believed to have taken play at the People’s Theatre in the North Korean capital, Pyongyang.

Pictures released by state-run newswire KCNA showed rows of uniformed officials clapping in delight at their nation’s progress in developing a weapon of mass destruction.

Last week’s test of a massive hydrogen bomb, just weeks after the country fired off two new intercontinental ballistic missiles (ICBM) capable of reaching US shores, prompted international condemnation and a call for tougher sanctions on the rogue nation.

The US and its allies feared there would be another ICBM test on Saturday to mark the North’s 69th anniversary of its founding day.

Instead, a grinning Mr Kim, praised nuclear weapons developers, including chief scientist Ri Hong Sop and Hong Sung Mu for “taking the lead” in attaining the “final goal of completing the state nuclear and economic development.”

They and their engineers were treated to a concert of patriotic songs and a lavish banquet, during which Mr Kim spurred them to make “redoubled efforts.” Ri, the head of North Korea’s Nuclear Weapons Institute, and Hong, deputy director of the ruling Workers’ Party of Korea’s munitions industry department, have both been blacklisted by the United Nations, US and South Korea.

While their leaders celebrated, ordinary North Korean citizens filed into the Kumsusan Palace of the Sun to pay their respects to the embalmed bodies of founding father Kim Il Sung and his son and successor Kim Jong Il.

KCNA said service personnel and civilians, including children, laid floral bouquets at statues of the deceased leaders across the country, while enjoying art performances and dance parties.

Kim sat with his wife Ri at the gala Credit: AFP

In an interview published in French newspaper Le Journal de Dimanche on Sunday, UN Secretary General Antonio Guterres, warned the confrontation over North Korea’s nuclear and missile programme was the world’s worst crisis in years.

The US will push on Monday for a new UN Security Council resolution that would impose an oil embargo on the North, an assets freeze on Kim Jong-un, and an end to payment of North Korean migrant workers.

On Sunday, the UN revealed that North Korea had illegally exported coal, iron and other commodities worth at least $270 million to China and other countries including India, Malaysia and Sri Lanka in the six month period ending in early August, in violation of existing UN sanctions.